Bis(carboxyphenyl)esters of benzenedisulfonyl halides

ABSTRACT

Aromatic dicarboxylic acids having three or more phenylene groups and two sulfonate linkages. They are prepared by oxidation of (A) bis-toluenesulfonate ester of a bis-phenol or (B) mbenzenedisulfonate of a cresol. These dicarboxylic acids are polymerizable with glycol to produce thermally stable polyesters.

States Patent Unite [15] 3,682,999 Rein [451 Aug. 8, 1972 [54]BIS(CARBOXYPHENYL)ESTERS OF [56] References Cited 72:3ENZENEI:)ISULFON.YL liALIDES UNITED STATES PATENTS PScataway 2,615,91310/1952 Widmer et al ..260/456 P [73] Ass1gnee: Mobil Oil Corporation3,518,294 6/1970 Rein....- ..260/456 P [22] Flled: 1969 PrimaryExaminer-Leon Zitver [21] Appl. No.: 880,517 Assistant Examiner-L. B.DeCrescente 0 Attorney-Oswald G. Hayes, Donald L. Dickerson and RelatedUS. Application Data Hastings Trigg [62] Division of Ser. No. 621,774,March 9, 1967,

Pat. No. 3,518,294. [571 ABSTRACT Aromatic dicarboxylic acids havingthree or more [52] US. Cl ..260/456P phenylene groups and two sulfonatelinkages. They [51] Int. Cl ..C07c 143/68 are prepared by oxidation of(A) bis-toluenesulfonate [58] Field of Search ..260/456 P ester of abis-phenol or (B) m-benzenedisulfonate of a cresol. These dicarboxylicacids are polymerizable with glycol to produce thermally stablepolyesters.

2 Claims, No Drawings BIS(CARBOXYPHENYL)ESTERS OF BENZENEDISULFONYLHALIDES REFERENCE TO RELATED APPLICATIONS This application is a divisionof copending application Ser. No. 621,774, filed Mar. 9, 1967, now US.Pat. No. 3,518,294.

BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates to aromatic dicarboxylic acids. It is more particularlyconcerned with novel aromatic dicarboxylic acids having three or morephenylene groups and two sulfonate linkages.

2. Description of the Prior Art Polyesters having good fiber formingproperties have been prepared by reacting aromatic dicarboxylic acidssuch as terephthalic acid with a glycol. Frequently, if the acidcontains more than one phenylene group the polyester will have greaterthermal stability.

Aromatic dicarboxylic acids have been prepared by oxidizing methylsubstituted aromatic compounds with molecular oxygen-containing gas(e.g., US. Pat. Nos. 2,245,528 and 3,036,122). When, however, aplurality of phenylene groups have been linked with groups such assulfite, carbonate, and oxalate, with methyl groups on the terminalphenyls, they do not undergo such oxidation. Thus, the desideratum is astable linking group that will permit oxidation to the dicarboxylicacid.

SUMMARY OF THE INVENTION It is the discovery of this invention that aplurality of phenylene groups linked with sulfonate groups and havingmethyl groups on the terminal phenyls can be readily oxidized with anoxygen-containing gas.

Accordingly, this invention provides aromatic dicarboxylic acids havingthe structural formulas:

L0- HOOCOE) Q --CRR" R J:

and

0 R R 3 t i wherein R is hydrogen, t-butyl, halogen, nitro, or alkoxyand R and R" are alkyl (C,-C

DESCRIPTION OF SPECIFIC EMBODIMENTS The compounds of this invention arearomatic dicarboxylic acids having at least three phenylene groups withsulfonate linkages, having the formulas defined in the Summary of theInvention. Each type is produced by oxidation of the correspondingmethyl derivative with molecular oxygen-containing gas.

PRECURSORS FOR OXIDATION In the case of preparing compounds of formulaA, a

bis-phenol is esterified with a toluenesulfonyl halide to form themethyl derivative to be oxidized, i.e. the compound of formula A havingmethyl groups instead of the formula:

HO R on iD C R it" AR wherein R and R" are alkyl (C -C and R ishydrogen, t-butyl, halogen, nitro, or alkoxy and R and OH can occupyany, but dissimilar, ortho, meta or para position. Non-limiting examplesof the bis-phenol reactants are 2,2-bis(m-hydroxyphenyl) butane;2,2-bis(phydroxyphenyl)-4-methylpentane;2,2-bis(m-hydroxyphenyl)-n-heptane;2,2-bis(4-hydroxy-3-tertiarybutyl)-propane;2,2-bis(4-hydroxy-3-chlorophenyl) propane;2,2-bis(4-hydroxy-5-nitrophenyl) propane;2,2-bis(4-hydroxy-3-methoxy-phenyl) propane; and2,2-bis(p-hydroxyphenyl) propane (Bis-phenol A).

The toluenesulfonyl halides are preferably the chlorides, althoughbromides and iodides can be used. Typical reactants arep-toluenesulfonyl chloride, 0- toluenesulfonyl chloride,o-toluenesulfonyl bromide and p-toluenesulfonyl iodide.

The reaction between the bis-phenol reactant and the toluenesulfonylhalide reactant can be carried out by any of the methods well known inthe art. As hydrogen halide is produced in the reaction, a base, such ascaustic or a tertiary amine, is used to remove hydrogen and drive thereaction toward completion. Thus, the bis-phenol reactant can bedissolved in aqueous sodium hydroxide and reacted with thetoluenesulfonyl halide. A particularly feasible method, employingpyridine, is described by Tipson, J. Org. Chem., 9, 235 (I944).Preferably, the reaction is carried out at about room temperature orlower.

In the case of preparing compounds of Formula B, a cresol reactant isesterified with m-benzenedisulfonyl halide, preferably the chloride, toform the methyl derivative to be oxidized, i.e., the compound of FormulaB with methyl groups instead of carboxyl groups.

The cresol reactant comtemplated herein is a compound having theformula:

wherein R can be tertiary-alkyl, methyl, nitro, cyano, halogen, alkoxy,or sulfo (or salt) n is 0 to l, and R and -CH can occupy any, butdissimilar, ortho, meta, or para position. Typical cresol reactantso-cresol, mcresol, p-cresol, 4-chloro-m-cresol, 2-nitrop-cresol,Z-methoxy-p-cresol, 4-nitro-mcresol, 3- tertiary-butyl-m-cresol.2-bromo-p-cresol, 3.4-dimethylphenol, and 3-sulfo-p-cresol.

The esterification is carried out as described hereinbefore, suitablyusing the method of Tipson. supra.

OXIDATION TO DICARBOXYLIC ACID The solvent used in the process of thisinvention is a lower (C -C fatty acid, i.e., acetic acid, propionicacid, or butyric acid; or a mixture of two or more lower fatty acids. Ingeneral, the concentration of creaylic arylsulfonate reactant will bebetween about 2 per cent and about 20 per cent, by weight of the lowerfatty acid and preferably between about 7 per cent and about 12 percent.

The oxidation reaction is effectively catalyzed by a cobalt salt of alower (C -C fatty acid, i.e., cobalt acetate, propionate, or butyrate.Between about 0.1 per cent and about 5 per cent, based on the weight offatty acid, is generally sufficient.

The promoter, or reaction activator, used in the present oxidationprocess is a methylenic ketone, such as methyl ethyl ketone, methyln-propyl ketone, diethyl ketone, 2,4-pentanedione, and 2,5-hexanedione.The concentration of the promoter should be between about 0.5 per centand about per cent, by weight of the lower fatty acid.

The oxidation is effected by contacting the reaction mixture withmolecular oxygen-containing gas at an oxygen partial pressure of betweenabout 100 and about 1,000 p.s.i.g. While air or other oxygen-containinggas can be used, relatively pure oxygen is preferred. Generally, theoxidation reaction is carried out at a temperature of between about 125C. and about 145 C., preferably at about 130 C.

The products of the process of this invention are novel arylcarboxylicacids having the formulas:

EXAMPLE l A 300 ml. autoclave was charged with mixture of MEK (5.0g,0.70 mole), cobalt acetate tetrahydrate (2.5g, 0.01 mole) and aceticacid (100 ml.). The solution was stirred rapidly and maintained attemperature of about 125C. while pure oxygen was passed in at a rate soas to sustain the pressure at 250 psi. An exothermic reaction proceededand after 100 psi, oxygen was consumed, the mixture was cooled.4,4-lsopropylidene-di-phenyl 4",4'"-di-toluenesulfonate (10g., 0.0187mole), MEK (2.5g., 0.35 mole) and acetic acid (25 ml.) was then addedand the reaction was continued at about 125C. and 250 psi until theoxygen absorption ceased. The product, a white ppt. was filtered, washedwith acetic acid, cold water and dried in an oven at 109C. The yield ofcrude 4,4-isopropy1idenedi-phenyl 4",4"'-di-carboxybenzenesulfonate was9.4g. (84% the theoretical) m.p. 2714 C.

Neutralization Equivalent Calc. 298

Neutralization Equivalent Found 301 The dibasic acid was converted toits corresponding dimethyl ester (m.p. 1047 C), by treatment with a 10%BF -MeOH solution. The N.M.R. spectrum of the di-methyl ester wasconsistent with the proposed structure (l).

H fl C11: 8 E

' 0m0o- '-s--O r: 7 ---s- 0 .0011,

@ H H 0 cm 0 (A) if s o 1100c l -CRR R J2 and R 1 r** l -TG 11000 0EXAMPLE 2 A 300 ml. autoclave was charged with a mixture of di-4-tolyl1',3'-benzene di-sulfonate (20.9g., 0.05 mole), MEK (6.0g, 0.83 mole),cobalt acetate tetrahydrate (2.5g, 0.01 mole) and acetate acid ml.). Thesolution was stirred rapidly and maintained at a temperature of about C.while pure oxygen was passed in at a rate so as to sustain the oxygenpressure at 250 psi. After the oxygen absorption ceased, the mixture wascooled and removed from the autoclave. The product, a white ppt., wasfiltered hot, washed with cold acetic acid, cold water, and dried in anoven at 109 C. The yield of di(4-carboxyphenyl)-1-3'-benzene-di-sulfonate was 16.2g., (68 percent of theoretical) m.p.319-22.

Neutralization Equivalent Calc. 245

Neutralization Equivalent Found 239 The N.M.R. spectrum of the productsupported the proposed structure; the dibasic acid was converted to itscorresponding di-methyl ester, m.p. 33C.

Although the present invention has been described with preferredembodiments, it is to be understood that modifications and variationsmay be resorted to, without departing from the spirit and scope of theinvention, as those skilled in the art will readily understand. Suchvariations and modifications are considered to be within the purview andscope of the ap pended claims.

lclaim:

1. Aromatic dicarboxylic acids having the formula:

mnthoxy.

2. Di( 4-carboxyphenyl )-l ,3 -benzene-disulfonate.

2. Di(4-carboxyphenyl)-1'',3''-benzene-disulfonate.